Intervalsconfidence 0.83
3 × 3km
Colin Dismuke50 km / marathon build
Source: own Strava export
Intervals
3 × 3km
Distance
16.3 km
Moving
69:13
Rep pace
3:45/km
Avg HR
164 bpm
Reps
3
Planned vs actual · TrainingPeaksPlanned 1:07:51 · 16.0 kmRan 1:09:13 · 16.3 kmIF 1.57TSS 284
Shape of the sessionEasyWorkFastest
warm up
cool down
0:003 × work / float69:13
The decode
A progressive threshold set of three 3km reps demanded a controlled rise in output across the work, with limited recovery and residual fatigue from the recent marathon making the final gear change harder to access.
The progression held from 3:53/km to 3:43/km to 3:38/km, while heart rate rose from 169 to 178 to 182; the final rep was fastest, but the session note indicated that the last increase in effort was not fully available.
Rep splits
| Rep | Time | Pace | HR | Float |
|---|---|---|---|---|
| 1 | 11:39 | 3:53/km | 169 | 2:27 |
| 2 | 11:09 | 3:43/km | 178 | 2:36 |
| 3 | 10:54 | 3:38/km | 182 | 4:60 |
0.83
confidence
What the engine saw
- 3 work intervals detected from lap markers, confirmed by clear pace separation.
- Recoveries average 201s.
Calibration flags
- Running power threshold estimated from the athlete's half-marathon best efforts (60-min power 476 W, 95% of 20-min power 460 W). Treat power zones and load as ±3%.
- Zones and running threshold are one snapshot, read 2 Jul 2026 and applied to every session in the archive. An older session is scored against today's zones, not the zones the athlete trained with then.
Engine read · editorial decode by Splits
Time in zone
Heart rate
Z1
Recovery10%
Z2
Endurance17%
Z3
Tempo22%
Z4
Threshold15%
Z5
VO₂max35%
Pace
Z1
Easy48%
Z2
Endurance6%
Z3
Tempo29%
Z4
Threshold17%
Z5
VO₂max0%
Z6
Speed0%
Power
Z1
Recovery0%
Z2
Endurance15%
Z3
Tempo36%
Z4
Threshold39%
Z5
VO₂max10%
Z6
Anaerobic0%
Z7
Neuro0%
Aerobic decoupling · Pa:HR+5%
Effort & efficiency
0.73
Running effectiveness
speed per watt/kg, reps
6.1 w/kg
Power-to-weight
rep average
2.59
Efficiency factor
norm. power per bpm
1.03
Variability index
1.0 = perfectly even power
2.8%
Rep consistency
pace spread across reps, lower is tighter
1760 kJ
Total work
mechanical energy
1142 kcal
Energy
estimated burn
716 bpk
Cardiac cost
heartbeats per km
50%
Above threshold
≥ 164 bpm (Z4+)
-0:07/km
Split balance
negative split, faster 2nd half
Conditions-adjusted pace26°C · +59 m
Actual
3:45/km
Grade-adjusted
3:45/km
Heat-adjusted
3:35/km
−10s/km
True effort
3:35/km
−10s/km
The rep pace re-expressed for flat ground and cool air, the effort, not the clock. The gap between actual and true effort is the day's hidden work: conditions were taxing the clock.